Heart disease and cerebrovascular disease are the first and third leading causes of mortality in the United States, accounting for 887,000 (38 percent) of all deaths annually. The total direct and indirect costs associated with cardiovascular disease have been estimated at $326.6 billion each year. Abnormal lipid and lipoprotein levels, a common problem among more than 100 million (about 20 percent), of American adults, have been associated with an increased risk for heart attack and cerebrovascular disease. While pharmacologic intervention can help to control abnormal lipid and lipoprotein levels in adults, a debate continues over the efficacy of pharmacologic interventions because of deleterious side effects and costs. Aerobic exercise is a low-cost, nonpharmacologic intervention that has few side effects and is available to most of the general public. Consequently, there has been a continued interest in aerobic exercise as a nonpharmacologic approach for maintaining adequate lipid and lipoprotein levels in adults Recent reviews of literature on this topic have synthesized research using the "traditional" approach (chronologically arranging and describing the studies, perhaps by subtopic), which may result in subjective, nonreplicable conclusions. Consequently, the overall magnitude and direction of effect, as well as the relationships among such variables as subject characteristics, experimental design quality, training program characteristics, and how they contribute to changes in lipid and lipoprotein levels, is not clear. Meta-analysis is a method of pooling the results of separate studies. It is a quantitative approach for increasing statistical power of primary end points and subgroups, resolving uncertainty when studies disagree, improving estimates of effect sizes, and answering questions not posed at the start of individual trials. To date, no recent study has conducted a detailed, quantitative synthesis of the existing literature regarding the role of aerobic exercise as a nonpharmacologic intervention/or improving lipid and lipoprotein levels in adults. In this proposed project, the meta-analytic approach will be used to synthesize research on the overall magnitude of effect as well as the relationships among variables associated with aerobic exercise and lipid and lipoprotein levels in adults.